From detection to decision: the role of clinical laboratories in combating emerging infectious diseases

Background: Clinical laboratories support emerging infectious disease responses through pathogen identification and timely diagnostic information. Objective: To examine how laboratory testing contributes to diagnosis and clinical decisions using selected published evidence. Methods: A preliminary narrative synthesis examined three selected studies of clinical metagenomic sequencing and molecular point-of-care testing. Study-specific findings were summarized without statistical pooling; this was not a completed scoping review. Results: In a prospective study of 204 patients with suspected neurological infections, metagenomic sequencing identified 13 infections missed by clinical testing at the source hospital; seven of these diagnoses guided treatment. A separate seven-year evaluation of 4,828 cerebrospinal fluid samples found 697 positive samples (14.4%). In its clinically characterized subset, 48 of 220 infectious diagnoses (21.8%) were identified by sequencing alone. In a non-randomized COVID-19 study involving 499 point-of-care patients and 555 controls, median time to results was 1.7 versus 21.3 hours. Conclusion: Selected evidence indicates that advanced diagnostics can provide additional diagnoses and faster results, with treatment implications in some cases. These findings do not establish consistent improvements in patient outcomes or generalizability across emerging infections.